The Queensland government will quarantine all people arriving from Adelaide as it races to track down 7000 people who have entered the state from the city in the past seven days.
Queensland followed Western Australia, the Northern Territory and Tasmania in imposing travel restrictions on arrivals from South Australian capital on Monday.
The Adelaide COVID-19 cluster, linked to a worker at a quarantine hotel, has now spread to 17 people in the city.
Queensland Premier Annastacia Palaszczuk says the new restrictions on arrivals from Adelaide will come into force 11.59pm on Monday.
"This cluster outbreak is of concern. It's not like the cluster outbreaks we've had in Queensland, but we do really hope that Adelaide does get on top of that very, very quickly," she told reporters on Monday.
Chief Health Officer Jeannette Young urged any of the 7000 people who have arrived in the state from Adelaide since last Monday to get tested and immediately self-isolate.
"So if they're in their homes here in Queensland because they're returning residents, or they're visiting or say on holidays, (I'm asking) that they isolate themselves from other people until it's been 14 days since they left Adelaide," she said.
Brisbane Lord Mayor Adrian Schrinner is isolating after talking to Dr Young about his trip to Adelaide last week.
"I'm feeling healthy and well, but will be following today's Queensland health directive and encourage anyone else who has been in Adelaide ... to do the same," he tweeted.
Dr Young said the restrictions would remain in place until Adelaide has gone for 28 days without an unlinked case of community transmission.
She said restrictions on the SA capital wouldn't automatically impact the status of Victoria or NSW.
"If NSW and Victoria start seeing cases in their communities, wherever they've come from, whether they've come from Adelaide or from anywhere else, then of course we would make a decision about whether or not we have to declare further hotspots," Dr Young said.
Health Minister Yvette D'Ath urged businesses, venues and organisations to ensure that they are recording the details of all customers or patrons.
She said it was the obligation of individuals, and of businesses and organisations to ensure people were checking-in to allow the government to trace contacts during outbreaks.
"We have had people arriving from Adelaide, even today, in Brisbane, Cairns and Gold Coast, so we need to be vigilant," Ms D'Ath said.
Dr Young was confident Queensland had a robust hotel quarantine system, which involves a high degree of caution when moving patients to hospital, and regular virus tests for workers.